660
FXUS66 KMTR 110532
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
932 PM PST Wed Dec 10 2025

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 106 PM PST Wed Dec 10 2025

 - Hazardous beach conditions through Friday

 - Tule fog and stratus continue for the North and East Bay

 - Light rain remains possible next week

&&

.UPDATE...
Issued at 911 PM PST Wed Dec 10 2025

If you`ve looked at satellite imagery this evening you`ll see pretty
much a rinse and repeat of last night`s fog. Ceiling heights are
around 500 to 600 feet with localized lower ceilings across portions
of the North Bay. Visibilities have started to drop across the North
Bay and East Bay (1 1/4SM at Santa Rosa Airport, 3SM at Livermore
Airport, 5SM at Byron and Concord Airport). Localized dense fog is
possible during the early morning hours across the North Bay and
East Bay Valleys. This pattern is likely to persist into the weekend
as a relatively stable pattern and high pressure continues.

&&

.SHORT TERM...
Issued at 106 PM PST Wed Dec 10 2025
(This evening through Thursday)

San Francisco and the immediate bay shoreline stayed mostly cloud
free this morning while the North Bay, South Bay, and East Bay
valley locations remain socked in with low clouds. This is as
offshore flow just above the surface pushed tule fog and/or
stratus into these areas. We have seen these clouds erode in the
South Bay while they remain over the far interior East Bay and
North Bay. We are expecting these clouds to mix out and give way
to a few hours of sun, except across the far interior East Bay and
bay side parts of Marin County. This has made for a challenging
forecast over the past week or so, especially with respect to
afternoon maximum temperatures.

Look for more of the same overnight and into early Thursday
morning with tule stratus and/or fog to return to much of the
aforementioned areas. Elsewhere, we are expecting mostly clear
skies overnight with temperatures dropping into the 40s across
much of the lower elevations and mid-to-upper 30s in the interior
Central Coast.

For Thursday, expecting temperatures to warm a degree or two in
the non-cloud covered areas as a ridge of high pressure continues
to build over the region. Again, places which happen to see full
sunshine are likely to be warmer than currently forecast. But on
the other hand, cooler than currently forecast if cloud cover
holds on throughout the day.

&&

.LONG TERM...
Issued at 106 PM PST Wed Dec 10 2025
(Thursday night through next Tuesday)

Temperatures will warm by a few degrees each day through Saturday
as the mid-to-upper level ridge axis shifts inland. This will be
the beginning of the ridge breaking down over our region. Thus, we
are likely to return closer to normal temperatures (still likely
up to 10 degrees above seasonal averages) and potentially
unsettled weather conditions as zonal flow returns to the region,
especially across the North Bay. This would bring the potential
for light rain to the North Bay and Bay Area by Monday or Tuesday
with chances lingering through the middle of next week. However,
the clusters do not point to a significant trough developing until
around December 20th.

&&

.AVIATION...
(06Z TAFS)
Issued at 932 PM PST Wed Dec 10 2025

VFR continues except for areas of fog and stratus /LIFR-IFR/ in
the East Bay and the North Bay. Strong thermal and height ridging
continues aloft across the forecast area, while lower elevations
in the East Bay and the North Bay will have either continuing or
increasing fog (including possibly patchy dense fog) and stratus
/VLIFR-IFR/ tonight and Thursday morning. Patchy fog and stratus
will redevelop over the South Bay as well tonight and Thursday
morning. Offshore winds continue due to currently WMC-SFO 5.8 mb
and SAC-SFO 2.1 mb pressure gradients. Forecast mix out times of
fog and stratus for Thursday are near persistence i.e. near today`s
mix out times. The highest probability of VFR for the 06z TAFs
continues over the north Central Coast.

Vicinity of SFO...VFR is continuing so far for the evening, then
it`s a low to moderate confidence VFR forecast for late tonight
and Thursday morning. The Oakland upper air sounding showed a
somewhat shallower layer (~ 540 feet) beneath the lower level
temperature inversion, a result of additional large scale
compressional warming aloft with the high pressure system. This
layer depth is not ubiquitous across the Bay Area, but from data
analysis/detection it does seem to be true from the East Bay
nearest the Delta to the SF Peninsula vicinity KSFO and areas
southward. Bottom line is, if stratus forms and advects toward SFO
late tonight and Thursday morning it`s likely it`ll be IFR or lower,
possibly including fog. Will monitor satellite, observations, etc.
and amend the TAF if needed. Mainly light northeasterly winds.

SFO Bridge Approach...VFR. Slantwise visibility issues possible
especially during sunset and sunrise due to haze.

Monterey Bay Terminals...VFR. Surface winds mainly southeasterly 5
knots except up to 10 to 15 knots in the Salinas Valley late tonight
and Thursday morning. Winds temporarily shifting to variable or
locally onshore late Thursday afternoon and early evening. Winds
shifting back to southeasterly Thursday night.

&&

.MARINE...
(Tonight through next Tuesday)
Issued at 922 PM PST Wed Dec 10 2025

High pressure off the coast will maintain northerly fresh breezes
across the outer coastal waters with light to gentle breezes near
shore. Light offshore winds will continue from the Delta to the
San Francisco Bay and through the Golden Gate. A new, long period
northwesterly swell will last into this weekend.

&&

.BEACHES...
Issued at 922 PM PST Wed Dec 10 2025

Long period swell will reach the coast tonight - Friday. This
energy brings strong rip currents, an increased risk for sneaker
waves, and large breaking waves. This coincides with nice warm
weather, which will likely lure more people to the beach under a
false sense of security. A Beach Hazard Statement is in effect
through Friday evening. Respect the power of the ocean and never
turn your back on it.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Friday evening for CAZ006-505-
     509-529-530.

PZ...Small Craft Advisory until 3 PM PST Thursday for Pigeon Pt to Pt
     Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Canepa
MARINE...Canepa

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